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Charge asymmetries of top quarks at hadron colliders revisited

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Abstract

A sizeable difference in the differential production cross section of top- compared to antitop-quark production, denoted charge asymmetry, has been observed at the Tevatron. The experimental results seem to exceed the theory predictions based on the Standard Model by a significant amount and have triggered a large number of suggestions for “new physics”. In the present paper the Standard Model predictions for Tevatron and LHC experiments are revisited. This includes a reanalysis of electromagnetic as well as weak corrections, leading to a shift of the asymmetry by roughly a factor 1.1 when compared to the results of the first papers on this subject. The impact of cuts on the transverse momentum of the top-antitop system is studied. Restricting the \( t\overline t \) system to a transverse momentum less than 20 GeV leads to an enhancement of the asymmetries by factors between 1.3 and 1.5, indicating the importance of an improved understanding of the \( t\overline t \)-momentum distribution. Predictions for similar measurements at the LHC are presented, demonstrating the sensitivity of the large rapidity region both to the Standard Model contribution and effects from “new physics”.

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Authors and Affiliations

  1. Institut für Theoretische Teilchenphysik, Karlsruher Institut für Technologie, D-76133, Karlsruhe, Germany

    Johann H. Kühn & Germán Rodrigo

  2. Instituto de Física Corpuscular, Consejo Superior de Investigaciones Científicas-Universitat de València, Parc Científic, E-46980, Paterna (Valencia), Spain

    Germán Rodrigo

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  1. Johann H. Kühn
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  2. Germán Rodrigo
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Correspondence to Germán Rodrigo.

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ArXiv ePrint: 1109.6830

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Kühn, J.H., Rodrigo, G. Charge asymmetries of top quarks at hadron colliders revisited. J. High Energ. Phys. 2012, 63 (2012). https://doi.org/10.1007/JHEP01(2012)063

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